1. Field of the Invention
The present invention relates to a communication apparatus including a function of editing a video content recorded in a storage medium using, for example, a NAND type flash memory, and a terminal apparatus including the editing apparatus.
2. Description of the Related Art
Some television receiver or video recorder compatible capable of receiving terrestrial digital broadcasting includes a function of storing a received program content in a portable storage medium using a NAND type flash memory such as a memory card. Storing a desired program content in a storage medium by using this type of apparatus allows the user to play the above program content in another room, a place outside his/her house, or the like by loading the storage medium into another television reception apparatus or a personal computer. Note that the program content stored in the recording medium is encrypted for copyright protection. There is also proposed a technique of letting the above apparatus have a function of editing the program content stored in a storage medium. This function allows editing processing, e.g., deleting a portion of a program content and leaving only a necessary portion.
When the above program content is to be deleted/edited, for example, the following processing is conventionally performed. First of all, the stream data of an encrypted program content stored in a storage medium is decoded. That portion of the decoded data which corresponds to the deletion range designated by the user is deleted. Portions before and after the deleted portions are re-encoded, and the re-encoded stream data is re-encrypted. Thereafter, the stream data of the program content after this re-encryption is stored in the storage medium again (see, for example, Jpn. Pat. Appln. KOKAI Publication No. 2002-140883).
Such a conventional deleting/editing function requires multi-stage processing for the data of a program content stored in the storage medium, e.g., decrypting/decoding an encrypted program content, deleting a portion of the data, and re-encoding and re-encrypting the data after the deletion. Of these processes, the decoding process, re-encoding process, and re-encryption process of video data, in particular, require very large processing amounts, resulting in a very long time for editing processing. This problem becomes especially remarkable when a flash memory is used as a storage medium, because the read-in and write-out speeds of the flash memory are significantly slow.